The analytical power of flow cytometry makes it invaluable for numerous biomedical applications that require the enumeration of cell populations and the analysis of multicellular model systems or organisms. However, typical flow cytometers limit sample analysis flow to less than 250 μL/min, analytical rates to 70,000 cells/s, and particle diameters to less than 70 μm. These limitations are driven by a number of factors that include pressure induced by high linear velocity fluid flows, turbulence in wide channels, and the single point analysis of stochastically arriving particles. Therefore, flow cytometry requires significant additional sample preparation steps to be effective in the analysis of very rare cell populations, uses offline particle concentration to analyze particles in large volume samples, and requires special purpose large flow channel cytometers using low linear velocity hydrodynamic focusing in wide channels to analyze particles that are >70 μm in diameter at low analysis rates (200 particle/s). Such limitations severely reduce the effectiveness of flow cytometry in many critical applications including the detection of rare blood cell populations, the detection of pathogens in liquid samples, and large particle high throughput analysis model systems (e.g. multicellular model organisms, cellular spheroids, and one-bead-one-compound chemical libraries).
Therefore there is a great need for affordable flow cytometry systems that have an increased analytical rate, volumetric sample delivery and usable particle size while retaining the analytical properties of flow cytometry (sensitivity, resolution of free vs. bound probes, correlated multiparameter analysis) that make it the technology of choice for cell and particle analysis.